Spirax Sarco R1C, Installation And Maintenance Instructions Manual, Page: 7 / 12

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IM-P087-33 MI Issue 6
3.2.3 R1C output options:
PNP open collector outputs.
Use this output option to connect the R1C to a BEMS / EMS whose digital inputs are pulled-
down to 0 volts. The pnp outputs act like switches connected to the R1C’s power supply. During
normal trap operation, the pnp outputs will switch On and give out a voltage equal to the R1C’s
power supply minus 0.4 V. Their output resistance in this state is 220 ohms. If the trap fails, one
of the pnp digital outputs will switch Off.
NPN open collector outputs.
Use this output option to connect the R1C to a B /EMS whose digital inputs are pulled-up to a
positive voltage: The npn outputs act like switches connected to 0 volts. During normal trap
operation, the npn outputs will switch On, giving out 0 volts with an output resistance of
220 ohms. If the trap fails, one of the npn digital outputs will switch Off.
BEMS/EMS
R1C
PL1
1 2 3 4
4 3 2 1
PL2
white
red
black
Steel
conduit
Spiratec
SS1/WLS1
sensor
0 Volts
4 - 20 mA
analogue o/p
Load resistor
Waterlogged
digital o/p
Leaking
digital o/p
0 Volts
-
+
Fig. 6 Wiring diagram
Fig. 7 R1C with PNP outputs
Fig. 8 R1C with NPN outputs
+ Power
Input
EMS input
0 volts
+ Power
Input
EMS input
0 volts
Power supply
R1C
output R1C
output
PL1/2
PL1/3, 4
PL1/1
R
PL1/2
PL1/3, 4
PL1/1
R
Note: Ensure that the resistance from the body of
the sensor to the pipework is less than 1
W
.